Pattern transferred can and method for manufacturing the same

ABSTRACT

By touching a band type transfer mold member  13  formed with micro protrusion and recess parts  13   a  thereon on a can  11  and holding and pressing the can  11  and the band type transfer mold member  13  with a pattern surface forming mold member  14  and a press-supporting mold member  15,  a micro protrusions and recesses pattern  12  is transferred to the can. By using separate transfer mold members of the band type transfer mold member having the micro protrusion and recess parts and the pattern surface forming mold member having the pattern surface forming part to form the micro protrusion and recess patterns, the band type transfer mold member can be moved little by little or by a length equivalent to the circumference of the can or can be replaced in accordance with the number of cans to be processed whereby continuous transfer can be realized without being affected by build-up due to clogging or wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

TECHNICAL FIELD

This invention relates to a pattern transferred can and a method for manufacturing the same capable of producing cans in a large scale at a high speed by transferring patterns such as interference fringes of light (hologram), pictures and photographs in the form of micro protrusions and recesses to cans such as tinplate cans, steel cans including TFS or aluminum cans while avoiding influence by clogging.

BACKGROUND OF THE INVENTION

In metal containers such as tinplate cans, steel cans including TFS or aluminum cans for drink or food, decorations are applied on trunks of the cans by means of printing or other technique. A proposal has been made to apply to metal containers a design which is different from conventional decoration such as printing by expressing patterns such as rainbow-colored holograms (interference fringes), pictures and photographs in the form of micro protrusions and recesses and affixing the patterns on the metal containers thereby to differentiate the metal containers from others.

For example, as a method for affixing a hologram which is one of such micro protrusion and recess patterns directly on a metal container, Japanese Patent Application Laid-open Publication No. Hei 2-32946 discloses a method for producing a container with a hologram in which laser interference ray is irradiated on a photoresist and micro protrusions and recesses are formed on the surface by development and a negative of electroforming made of nickel having this pattern of protrusions and recesses copied thereon is prepared. By bringing the outer surface of the metal container into rolling contact with this negative of electroforming under pressure, the micro protrusion and recess pattern is transferred and the hologram etc. is thereby reproduced on the outer surface of the metal container.

Japanese Patent Application Laid-open Publication No. 2002-508539 discloses a method for transferring a holography image on a metal surface in which, in the same manner as in the above publication, a mother shim (negative image) made of nickel is produced by electroforming from a master hologram (positive image) made on a photoresist and plural sister shims (positive images) are made from this mother shim also by electroforming and then, if necessary, the hologram surface of the sister shim is hardened. Further, after transferring the positive images of the sister shim to the surface of a printing roll, processing including hardening of this surface (negative image) are made and the holography image is transferred by embossing it on the surface of a can by this printing roll.

However, in both of the method of directly transferring the micro protrusion and recess pattern by pressing the outer surface of a metal container to a negative of electroforming made of nickel and the method of directly transferring the micro protrusion and recess pattern by pressing and rotating the metal container against the printing roll, slip tends to be caused in most portions where the rotating metal container comes into contact with the negative of electroforming or the printing roll and, as a result, material of the metal container such as an aluminum can, a tinplate can, or a steel can including TFS can intrudes into the micro protrusion and recess pattern and causes clogging of the pattern. Thus, in these methods, transfer can be made only for several cans to several scores of cans.

For this reason, for achieving transfer of the micro protrusion and recess pattern in a stable manner, it is necessary to clean the electroforming negative or printing roll formed with the micro protrusion and recess pattern every time and this makes it difficult to realize a large scale production at a high speed.

In hot stamp printing, as different from the direct forming of a micro protrusion and recess pattern, a hot stamping foil is adhered to a can. It is, however, also difficult to realize a large scale production at a high speed by this method and there is also a problem of making an extra processing of surface coating after adhesion of the foil.

It is, therefore, an object of the present invention to overcome the above described problems of the prior art technique and provide a pattern transferred can and a method for manufacturing the same capable of achieving a large scale production at a high speed without being affected by clogging due to transfer of micro protrusion and recess patterns representing photographs, pictures or interference fringes (hologram).

SUMMARY OF THE INVENTION

Studies made by the inventors of the present invention, for achieving the above described object of the invention, about clogging which occurs in case a micro protrusion and recess pattern is transferred to a metal container have resulted in the finding, which has led to the present invention, that the problems of build-up due to clogging and wear of micro protrusions and recesses are unavoidable so long as transfer is made by pressing micro protrusions and recesses even if surface processing such as hardening micro protrusions and recesses is made and that these problems can be overcome by disposing of a micro protrusion and recess part which has become unusable due to build-up and supplying a new micro protrusion and recess part continuously.

More specifically, by separating a micro protrusion and recess part of a transfer mold from a pattern surface forming part of the transfer mold, forming the micro protrusion and recess part on a band type mold member and forming a relief pattern on a pattern surface forming mold member, and moving the band type transfer mold member little by little or by a length equivalent to the circumference of a can in accordance with the number of cans to be processed, continuous transfer of the pattern can be realized without being affected by build-up due to dogging and wear of micro protrusions and recesses.

A pattern transferred can defined in claim 1 has micro protrusion and recess patterns transferred by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member.

According to this pattern transferred can, micro protrusion and recess patterns are transferred by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member and, by forming the micro protrusion and recess patterns by using separate mold members of the band type transfer mold member having micro protrusion and recess parts and the pattern surface forming mold member having a pattern surface forming part, the band type transfer mold member can be moved little by little or by a length equivalent to length of the circumference of a can or can be replaced in accordance with the number of cans to be processed whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of micro protrusions and recesses and a large scale production at a high speed can thereby be realized.

A pattern transferred can defined in claim 2 has, in addition to the feature of claim 1, the feature that the micro protrusion and recess patterns are transferred to the can by moving the band type transfer mold member to the pattern surface forming mold member, and the press-supporting mold member in a relative movement.

According to this pattern transferred can, the micro protrusion and recess patterns are transferred to the can by moving the band type transfer mold member to the pattern surface forming mold member and the press-supporting mold member in a relative movement. By moving the band type transfer mold member in a relative movement little by little or by a length equivalent to the circumference of the can, continuous transfer can be realized without being affected by build-up due to clogging and wear of protrusions and recesses whereby a large scale production at a high speed can be achieved.

A pattern transferred can defined in claim 3 has, in addition to the feature of claim 1 or 2, the feature that micro protrusions and recesses of the micro protrusion and recess parts are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can.

According to this pattern transferred can, micro protrusions and recesses of the micro protrusion and recess parts are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can and, therefore, a hologram pattern can be formed with the micro protrusion and recess pattern in the shape of protrusions or ridges and, moreover, by forming the protrusions or ridges extending in parallel to the circumferential direction of the can, discharge of material of the can be facilitated whereby build-up due to dogging is prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

In the pattern transferred can of claims 1-3, disposition of the micro protrusions and recesses in the pattern surface is not always coincidental for each can but the quality of the micro protrusion and recess patterns changes in the direction of transfer whereby the pattern transferred cans of these claims can be differentiated from the pattern transferred cans in which the micro protrusions and recesses are directly formed on the can.

A method for manufacturing a pattern transferred can defined in claim 4 is characterized by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member thereby to transfer a pattern surface formed with micro protrusions and recesses to the can.

According to this method for manufacturing the pattern transferred can, by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member, a pattern surface formed with micro protrusions and recesses is transferred to the can. By using separate transfer mold members of the band type transfer mold member having the micro protrusion and recess parts and the pattern surface forming mold member having the pattern surface forming part to form the micro protrusion and recess patterns, the band type transfer mold member can be moved little by little or by a length equivalent to the circumference of the can or can be replaced in accordance with the number of cans to be processed whereby continuous transfer can be realized without being affected by build-up due to dogging or wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 5 has, in addition to the feature defined in claim 4, the feature that the band type transfer mold member is moved in a relative movement to the pattern surface forming mold member and the press-supporting mold member thereby to renew the micro protrusion and recess parts of the band type transfer mold member and then the micro protrusion and recess patterns are transferred to the can.

According to this method for manufacturing a pattern transferred can the band type transfer mold member is moved in a relative movement to the pattern surface forming mold member and the press-supporting mold member thereby to renew the micro protrusion and recess parts of the band type transfer mold member and then the micro protrusion and recess patterns are transferred to the can. A part where build-up has occurred by processing a certain number of cans and transfer of the micro protrusion and recess parts has thereby become difficult at least can be replaced by a new micro protrusion and recess part for transfer whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 6 has, in addition to the feature defined in claim 5 the feature that renewed micro protrusion and recess patterns are transferred to the can by renewing the micro protrusion and recess parts over a length which is equivalent to or shorter than the circumferential length of the can.

According to this method for manufacturing a pattern transferred can, renewed micro protrusion and recess patterns are transferred to the can by renewing the micro protrusion and recess parts over a length which is equivalent to or shorter than the circumferential length of the can. By renewing the micro protrusion and recess parts over a length which is equivalent to the circumferential length of the can, a state in which the quality of the micro protrusion and recess patterns changes can by can be brought about and, by renewing the micro protrusion and recess parts at least partly, a state in which the quality of the micro protrusion and recess patterns in one can changes in the direction of transfer is brought about whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 7 has, in addition to the feature as defined in any of claims 4-6, the feature that protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member are formed on the surface of either the pattern surface forming mold member or the press-supporting mold member.

According to this method for manufacturing a pattern transferred can, protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member are formed on the surface of either the pattern surface forming mold member or the press-supporting mold member. By pressing protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member, transfer surface is reduced compared with a case where the entire micro protrusion and recess part is transferred whereby continuous transfer can be realized without being affected further by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved efficiently by reducing the amount of disposal of the band type transfer mold member.

A method for manufacturing a pattern transferred can defined in claim 8 has, in addition to the feature defined in any of claims 4-7, the feature that the micro protrusion and recess parts of the band type transfer mold member are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can.

According to this method for manufacturing a pattern transferred can, the micro protrusion and recess parts of the band type transfer mold member are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can and, therefore, a hologram pattern can be formed with the micro protrusion and recess pattern in the shape of protrusions or ridges and, moreover, by forming the protrusions or ridges extending in parallel to the circumferential direction of the can, discharge of material of the can is facilitated whereby build-up due to clogging is prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 9 has, in addition to the feature as defined in any of claims 4-8, the feature that the micro protrusion and recess patterns are transferred to the can with lubricant provided between the band type transfer mold member and the can.

According to this method for manufacturing a pattern transferred can, the micro protrusion and recess patterns are transferred to the can with lubricant provided between the band type transfer mold member and the can and, by making transfer in a lubricant atmosphere such as a positively applied lubricant or a coolant applied during DI processing of the can, adhesion of material of the can can be prevented and discharging of the material of the can is facilitated whereby build-up due to clogging can be further prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 10 has, in addition to the feature as defined in any of claims 4-9, the feature that the pattern surface forming mold member is disposed on the inside of the can and the band type transfer mold member and the press-supporting mold member are disposed on the outside of the can.

According to this method for manufacturing a pattern transferred can, the pattern surface forming mold member is disposed on the inside of the can and the band type transfer mold member and the press-supporting mold member are disposed on the outside of the can and, by such disposition of the three mold members, build-up due to clogging can be prevented whereby continuous transfer can be realized and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 11 has, in addition to the feature as defined in any of claims 4-9, the feature that the press-supporting mold member is disposed on the inside of the can and the band type transfer mold member and the pattern surface forming mold member are disposed on the outside of the can.

According to this method for manufacturing a pattern transferred can, the press-supporting mold member is disposed on the inside of the can and the band type transfer mold member and the pattern surface forming mold member are disposed on the outside of the can and, by such disposition of the three mold members, build-up due to clogging can be prevented whereby continuous transfer can be realized and a large scale production at a high speed can be achieved.

A method for manufacturing a pattern transferred can defined in claim 12 has, in addition to the feature as defined in any of claims 4-11, the feature that the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a concave surface with a center of curvature thereof being located on the same side as the center of the can.

According to this method for manufacturing a pattern transferred can, the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a concave surface with a center of curvature thereof being located on the same side as the center of the can. By this arrangement, in comparison with the prior art case where transfer is made between a pair of convex surfaces, undercut of an inner rotating gear wheel is restrained and build-up due to clogging can be prevented whereby continuous transfer can be realized and, by reducing the amount of disposal of the band type transfer mold member, a large scale production at a high speed can be efficiently achieved.

A method for manufacturing a pattern transferred can defined in claim 13 has, in addition to the feature as defined in any of claims 4-11, the feature that the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a convex surface.

According to this method for manufacturing a pattern transferred can, the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a convex surface and, by this arrangement, by making transfer between a pair of convex surfaces of the can and the mold member, the band type transfer mold member can be moved in a relative movement in a stable manner along the convex surface whereby a high speed movement of the band type transfer mold member can be realized and productivity can be improved. Further, a large scale production at a high speed can be efficiently achieved.

According to the pattern transferred can of claim 1, micro protrusion and recess patterns are transferred by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member and, by forming the micro protrusion and recess patterns by using separate mold members of the band type transfer mold member having micro protrusion and recess parts and the pattern surface forming mold member having a pattern surface forming part, the band type transfer mold member can be moved little by little or by a length equivalent to the circumference of a can or can be replaced in accordance with the number of cans to be processed whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of micro protrusions and recesses and a large scale production at a high speed can thereby be realized.

According to the pattern transferred can of claim 2, the micro protrusion and recess patterns are transferred to the can by moving the band type transfer mold member to the pattern surface forming mold member and the press-supporting mold member in a relative movement. By moving the band type transfer mold member in a relative movement little by little or by a length equivalent to length of the circumference of the can, continuous transfer can be realized without being affected by build-up due to clogging and wear of protrusions and recesses whereby a large scale production at a high speed can be achieved.

According to the pattern transferred can of claim 3, micro protrusions and recesses of the micro protrusion and recess parts are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can and, therefore, a hologram pattern can be formed with the micro protrusion and recess pattern in the shape of protrusions or ridges and, moreover, by forming the protrusions or ridges extending in parallel to the circumferential direction of the can, discharge of material of the can is facilitated whereby build-up due to clogging is prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

In the pattern transferred can of claims 1-3, disposition of the micro protrusions and recesses in the pattern surface is not always coincidental for each can but the quality of the micro protrusion and recess patterns changes in the direction of transfer whereby the pattern transferred cans of these claims can be differentiated from the pattern transferred cans in which the micro protrusions and recesses are directly formed on the can.

According to the method for manufacturing the pattern transferred can of claim 4, by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press supporting mold member, a pattern surface formed with micro protrusions and recesses is transferred to the can. By using separate transfer mold members of the band type transfer mold member having the micro protrusion and recess parts and the pattern surface forming mold member having the pattern surface forming part to form the micro protrusion and recess patterns, the band type transfer mold member can be moved little by little or by a length equivalent to the circumference of the can or can be replaced in accordance with the number of cans to be processed whereby continuous transfer can be realized without being affected by build-up due to clogging or wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

According to the method for manufacturing a pattern transferred can of claim 5, the band type transfer mold member is moved in a relative movement to the pattern surface forming mold member and the press-supporting mold member thereby to renew the micro protrusion and recess parts of the band type transfer mold member and then the micro protrusion and recess patterns are transferred to the can. A part where build-up has occurred by processing a certain number of cans and transfer of the micro protrusion and recess parts has thereby become difficult at least can be replaced by a new micro protrusion and recess part for transfer whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

According to this method for manufacturing a pattern transferred can of claim 6, renewed micro protrusion and recess patterns are transferred to the can by renewing the micro protrusion and recess parts over a length which is equivalent to or shorter than the circumferential length of the can. By renewing the micro protrusion and recess parts over a length which is equivalent to the circumferential length of the can, a state in which the quality of the micro protrusion and recess patterns changes can by can be brought about and, by renewing the micro protrusion, and recess parts at least partly, a state, in which the quality of the micro protrusion and recess patterns in one can changes in the direction of transfer is brought about whereby continuous transfer can be realized without being affected by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved.

According to this method for manufacturing a pattern transferred can of claim 7, protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member are formed on the surface of either the pattern surface forming mold member or the press-supporting mold member. By pressing protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member, transfer surface is reduced compared with a case where the entire micro protrusion and recess part is transferred whereby continuous transfer can be realized without being affected further by build-up due to clogging and wear of the micro protrusions and recesses and a large scale production at a high speed can be achieved efficiently by reducing the amount of disposal of the band type transfer mold member.

According to this method for manufacturing a pattern transferred can of claim 8, the micro protrusion and recess parts of the band type transfer mold member are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can and, therefore, a hologram pattern can be formed with the micro protrusion and recess pattern in the shape of protrusions or ridges and, moreover, by forming the protrusions or ridges extending in parallel to the circumferential direction of the can, discharge of material of the can is facilitated whereby build-up due to clogging is prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

According to this method for manufacturing a pattern transferred can of claim 9, the micro protrusion and recess patterns are transferred to the can with lubricant provided between the band type transfer mold member and the can and, by making transfer in a lubricant atmosphere such as a positively applied lubricant or a coolant applied during DI processing of the can, adhesion of material of the can can be prevented and discharging of the material of the can is facilitated whereby build-up due to clogging can be further prevented and continuous transfer can be realized and a large scale production at a high speed can be achieved.

According to this method for manufacturing a pattern transferred can of claim 10, the pattern surface forming mold member is disposed on the inside of the can and the band type transfer mold member and the press-supporting mold member are disposed on the outside of the can and, by such disposition of the three mold members, build-up due to clogging can be prevented whereby continuous transfer can be realized and a large scale production at a high speed can be achieved.

According, to this method for manufacturing a pattern transferred can of claim 11, the press-supporting mold member is disposed on the inside of the can and the band type transfer mold member and the pattern surface forming mold member are disposed on the outside of the can and, by such disposition of the three mold members, build-up due to clogging can be prevented whereby continuous transfer can be realized and a large scale production at a high speed can be achieved.

According to this method for manufacturing a pattern transferred can of claim 12, the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a concave surface with a center of curvature thereof being located on the same side as the center of the can. By this arrangement, in comparison with the prior art case where transfer is made between a pair of convex surfaces, undercut of an inner rotating gear wheel is restrained and build-up due to dogging can be prevented whereby continuous transfer can be realized and, by reducing the amount of disposal of the band type transfer mold member, a large scale production at a high speed can be efficiently achieved.

According to this method for manufacturing a pattern transferred can of claim 13, the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a convex surface and, by this arrangement, by making transfer between a pair of convex surfaces of the can and the mold member, the band type transfer mold member can be moved in a relative movement in a stable manner along the convex surface whereby a high speed movement of the band type transfer mold member can be realized and productivity can be improved. Further, a large scale production at a high speed can be efficiently achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outside perspective view of a pattern transferred can which is an embodiment of the pattern transferred can and the method for manufacturing the same according to the invention.

FIG. 2 is an explanatory view of a basic principle of manufacturing a pattern transferred can of an embodiment of the pattern transferred can and the method for manufacturing the same according to the invention.

FIGS. 3A and 3B are enlarged views of micro protrusion and recess parts of an embodiment of the pattern transferred can and the method for manufacturing the same according to the invention.

FIGS. 4A and 4B are partial plan view and partial vertical section of an embodiment of the pattern transferred can and the method for manufacturing the same according to the invention.

FIGS. 5A and 5B are partial plan view and partial vertical section of another embodiment of the pattern transferred can and the method for manufacturing the same according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Description will now be made about preferred embodiments of the invention with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a pattern transferred can and a method for manufacturing the same according to the invention. FIG. 1 is a perspective view showing an outside appearance of the pattern transferred can and FIG. 2 is an explanatory view showing the principle of manufacturing the pattern transferred can.

This pattern transferred can 10 has micro protrusion and recess patterns 12 transferred directly on a trunk portion 11 a of a metal can 11 such as a tinplate can, steel can such as a TFS (tin-free-steel) can or an aluminum can. By these micro protrusion and recess patterns 12, a hologram image made by interference fringes, for example, can be shown or a picture or photograph made by micro protrusions and recesses can be expressed.

The metal can 11 which constitutes material of the pattern transferred can 10 may be either a 2-piece can such as an aluminum can or a DI can made of steel or a 3-piece can which is made by welding the trunk portion.

Description will now be made about details of the pattern transferred can 10 and the method for manufacturing it. In this pattern transferred can 10, transferred micro protrusions and recesses 12 a and pattern surfaces 12 b such as a relief pattern on the basis of which the micro protrusion and recesses 12 a are formed are formed in two separate mold members. In addition to these mold members, a press-supporting mold member is used and, by using these three mold members together, the micro protrusion and recess patterns 12 are formed by transfer. A micro protrusion and recess part which has become unusable due to build-up etc. is disposed of while a new micro protrusion and recess part is added and thus continuous transfer is performed.

More specifically, as shown in the principle of manufacturing of FIG. 2, the three mold members are a band type transfer mold member 13 made in the form of a band on which micro protrusion and recess parts 13 a are formed, a pattern surface forming mold member 14 and a press-supporting mold member 15, said pattern surface forming mold member 14 and the press-supporting mold member 15 holding the band type transfer mold member 13 and the metal can 11 on opposite sides with the band type transfer mold member 13 being in touch with the outer surface of the trunk portion 11 a of the metal can 11. As shown in the example of FIG. 2, the pattern surface forming mold member 14 may be disposed on the outside of the metal can 11 and the press-supporting mold member 15 may be disposed inside of the metal can 11. Conversely, the pattern surface forming mold member 14 may be disposed on the inside of the metal can 11 and the press-supporting mold member 15 may be disposed on the outside of the metal can 11.

The pattern surface forming mold member 14 is disposed, as shown in FIG. 2, on the rear side of the band type transfer mold member 13 which in turn is disposed on the outer side of the metal can 11 and is formed with pattern surfaces (negative images) 14 a corresponding to pattern surfaces (positive images) 12 b formed on the metal can 11. In FIG. 2, the pattern surfaces 14 a are provided as two protruding surfaces, one being in a triangular shape and the other being in a circular shape. By forming the pattern surfaces 14 a in a surface (negative image) having a shape corresponding to a picture or a photograph, or in a surface (negative image) having a shape corresponding to one or more characters, or in surface (negative image) having a shape corresponding to a combination thereof, pattern surfaces 12 b (positive images) corresponding to these pattern surfaces 14 a (negative images) can be formed on the outer surface of the metal can 11.

This pattern surface forming mold member 14 constitutes one mold member disposed on the outside of the can of a normal pair of transfer mold members. In this example, as different from one mold member of normal transfer mold pair, a transfer surface 14 b of the pattern surface forming mold member 14 is formed in a concave surface. By this arrangement, when transfer is made, adhesion of material of the metal can 11 can be prevented and discharge of the material can be facilitated.

By forming the transfer surface 14b of the pattern surface forming mold member 14 in a concave surface, a significant difference is observed in comparison with a case where the pattern surface forming mold member 14 is formed in a convex surface in a conventional manner in that the amount of adhesion of material of the metal can 11 is reduced in a gravity measuring test of the adhesion of the material. Thus, it has been confirmed that the number of metal cans processed can be increased by this arrangement.

This pattern surface forming mold member 14 is provided in three parts of end portions and middle portion with guide members 16 which guide the band type transfer mold member 13 formed with micro protrusion and recess parts 13 a along the concave surface 14 b. The band type transfer mold member 13 is guided along the outside of the guide members 16 provided at the end portions and is guided along the inside of the middle guide member 16.

These guide members 16 may be formed as rotating guide members rotatable about center axis thereof or as non-rotating guide members or as a combination of a rotating guide member and a non-rotating guide member. For example, the middle guide member may be a non-rotating guide member and the guide member at the end portions may be rotating guide members.

In transferring a micro protrusion and recess part by using A conventional transfer mold member, a pattern surface forming mold member such as the mold member 14 is formed with a micro protrusion and recess part as a transfer mold on its pattern surface 14 a. In the pattern surface forming mold member 14 of the present invention, however, the micro protrusion and recess part is not formed. In this pattern surface forming mold member 14, however, the pattern surfaces 14 a are formed as protrusion and recess parts 14 c which are rough surfaces formed with protrusions and recesses (not shown). The protrusion and recess parts 14 c are formed by, e.g., shot blasting. The size of the protrusions and recesses of the protrusion and recess part 14 c of the pattern surface 14 a is larger by 10 times to 100 times than the protrusions and recesses of the micro protrusion and recess part 13 a and, by this arrangement, portions corresponding to the micro protrusion and recess part 14 c only are pressed and transferred without causing the entire surface of the micro protrusion and recess part 13 a of the band type transfer mold member 13 to come into contact with the metal can 11 whereby adhesion of material of the metal can 11 and wear of the micro protrusion and recess parts 13 a can be reduced in proportion to difference in the areas of protrusions and recesses between the two mold members and the number of the cans processed can thereby be increased.

The band type transfer mold member 13 which is formed separately from the pattern surfaces 14 a of the pattern surface forming mold member 14 is formed on the surface of a thin plate in the form of a band with the micro protrusion and recess parts 13 a. These micro protrusion and recess parts 13 a may, for example, have a pitch of the protrusions or recesses in the order of 0.5-5 μm and depth in the order of 0.5-20 μm and, by these protrusions and recesses, a hologram of interference fringes can be observed or a picture or photograph by the micro protrusions and recesses can be expressed and the micro protrusion and recess parts 13 a of the band type transfer mold member 13 can be transferred to the metal can 11 b by transfer processing.

The micro protrusion and recess parts 13 a of the band type transfer mold member 13 may, as shown in FIG. 3(a), have micro protrusions and recesses which are formed in the shape of independent protrusions or, as shown in FIG. 3(b), have micro protrusions and recesses which are formed in the shape of parallel ridges. In the case of independent protrusions, these protrusions may be arranged either in grid-like fashion or in staggered fashion so long as a hologram by interference fringes is observed.

Such band type transfer mold member 13 can be produced, for example, by, in the same manner as in conventional processes, irradiating laser interference beam on a photoresist to form micro protrusion and recess parts on the surface, copying these micro protrusion and recess parts by electroforming and preparing a band type thin plate made of nickel.

By using the negative made by electroforming in the form of a thin plate of nickel as the band type transfer mold member 13 in such a manner that the band type transfer mold member 13 touches the outer surface of the metal can 11 and holding and pressing the band type transfer mold member 13 and the metal can 11 on opposite sides with the pattern surface forming mold member 14 and the press-supporting mold member 15, a hologram etc. of the micro protrusion and recess patterns 12 is transferred to the outer surface of the metal can 11 by the micro protrusion and recess parts 13 a and the pattern surfaces 14 a and the pattern transferred can 10 thereby is produced.

As the pattern transferred can 10 is produced in this manner, it gradually becomes difficult to clearly transfer the micro protrusion and recess parts 13 a because build-up occurs due to clogging caused by adhesion of material of the metal can 11 or collapse of the micro protrusion and recess parts 13 a or wear of the micro protrusions and recesses occurs. Accordingly, as will be described more fully later, the band type transfer mold member 13 is moved in relative movement to the pattern surface forming in mold member 14 before a next transfer processing thereby to dispose of a portion of the micro protrusion and recess parts 13 a which is no longer usable for transfer and add new micro protrusion and recess parts 13 a.

The relative movement of the band type transfer mold member 13 is not limited to the illustrated example in which the movement is made in the direction of transfer but the band type transfer mold member 13 may be moved in any direction such as vertical direction crossing the direction of transfer and crossing direction to the direction of transfer so long as new micro protrusion and recess parts 13 a can be added.

Accordingly, in the band type transfer mold member 13 used for transfer, arrangement of the micro protrusion and recess parts 13 a in the form of ridges extending in parallel to the direction of transfer or, even in the case of the independent protrusions, arrangement of these protrusions in parallel to the direction of transfer is effective for preventing adhesion of material of the metal can 11 and build-up due to clogging in the transfer processing.

On the other hand, the press-supporting mold member 15 disposed on the inside of the metal can-11 and constituting the other part of the transfer mold is formed in the shape of a column which can be inserted in the trunk portion 11 a of the metal can 11. The metal can 11 is mounted on this press-supporting mold member 15 to cover the mold member 15 and transfer is made with the metal can 11 being clamped between the press-supporting mold member 15 and the pattern surface forming mold member 14 pairing with the mold member 15. The outer surface of the press-supporting mold member 15 is made a flat surface so that the mold member 15 can support the metal can 11 in close contact therewith.

The press-supporting mold member 15 may be formed on the outer surface thereof with protrusions and recesses by, e.g., shot blasting and the pattern surfaces 14 a of the pattern surface forming mold member 14 may be made flat surfaces which can support the metal can 11 in close contact therewith. By making either surface a flat surface and the other surface a protrusion and recess surface, the area where the micro protrusion and recess parts 13 a come into dose contact with the metal can 11 can be reduced and the life of the band type transfer mold member 13 can thereby be prolonged.

An apparatus for manufacturing the pattern transferred can 10 by using the three mold members of the band type transfer mold member 13, pattern surface forming mold member 14 and press-supporting mold member 15 will now be described with reference to FIG. 4.

In the apparatus 20 for manufacturing the pattern transferred can 10, a disk 23 is fixed via a key to a rotary shaft 22 which extends through a frame 21 of the apparatus and this disk 23 is driven and rotated by a belt 27 which is provided between a pulley 25 of a motor 24 fixed to the frame 21 and a pulley 26 provided at the lower end portion of the rotary shaft 22.

A plurality (six in the illustrated example) of can holder 28 which constitute the press-supporting mold member 15 are provided at an equal interval in the circumferential direction and the metal cans 11 can be mounted on the can holders 28 by fitting each of the metal cans 11 on the can holder with the bottom of the metal can 11 up.

Each of the can holder 28 has a support shaft 29 projecting downwardly and the support shaft 29 is rotatably mounted on the disk 23 via a bearing 30 and a gear wheel 31 fixed to the support shaft 29 is in meshing engagement with an internal gear 32 which is fixed to the frame 21.

By this arrangement, as the disk 23 is driven and rotated each of the can holders 28 rotates on the support shaft 29 and revolves around the outer periphery of the disk 23 on the rotary shaft 22.

In the apparatus 20 for manufacturing the pattern transferred can, a concave surface pressing mold 33 which constitutes the pattern surface forming mold member 14 is fixed to the frame 21 in a position opposite to the entire length of the outer surface (i.e., the circumference) of the rotating can holder 28 which revolves around the outer periphery of the disk 23 or a part thereof in such a manner that the concave surface of the transfer surface 14 b is opposed to the can holder 28.

A stamper 35 in the form of a coil which constitutes the band type transfer mold member 13 passes along guide members 36 provided in the middle portion and end portions of the stamper 35 and is disposed along the transfer surface 14 b. The stamper 35 in the form of a coil is wound on a rewind reel 36 and its forward end is fixed to a take-up reel 37. By an unillustrated take-up drive system, the stamper 35 is fed and wound on the take-up reel 37 so that a predetermined amount thereof is moved in a relative movement to the concave surface pressing mold 33.

The concave surface pressing mold 33 is disposed in such a manner that the stamper 35 touches the outer surface of the metal can 11 mounted on the can holder 28 and pressing and transfer can be made with the metal can 11 and the stamper 35 being held between the can holder 28 and the concave surface pressing mold 33.

In the disk 23 provided with six can holders 28 are provided a supply position 38 of the metal can 11 on the upstream side of the concave surface pressing mold 33 and a take-out position 39 of the metal can 11 on the downstream side of the concave surface pressing mold 33 and unillustrated automatic supply device and automatic take-out device are also provided.

The apparatus 20 for manufacturing the pattern transferred can, in some cases, is installed during the manufacturing process of the metal can and, in other cases, is installed while the metal can is not manufactured. In the former case, for example, the metal can 11 is supplied to the apparatus 20 for transfer processing in the state that lubricant is applied to the metal can 11.

Operation of the apparatus 20 having the above described structure will now be described together with a method for manufacturing the pattern transferred can.

First, the stamper 35 constituting the band type transfer mold member 13 formed with the micro protrusion and recess parts 13 a is positioned in front of the transfer mold 14 b by passing the the stamper 35 along the guide members 34 of the concave surface pressing mold 33.

Then, the motor 24 is driven to rotate the disk 23 and the metal can 11 is supplied to the supply position 38 and is mounted on the can holder 28 constituting the press-supporting mold member 15 which comes to the supply position 38 by fitting the metal can 11 on the can holder 28.

As the metal can 11 mounted on the can holder 28 arrives in front of the concave surface pressing mold 33, the metal can 11 is held and pressed between the concave surface pressing mold 33 and the can holder 28 with the stamper 35 being in contact with the outer surface of the metal can 11 and transfer thereby is started while the disk 23 is rotated before the concave surface pressing mold 33, the pattern surface 14 a formed on the concave surface pressing mold 33 and the micro protrusion and recess parts 13 a of the stamper 35 are simultaneously transferred to the metal can 11 mounted on the can holder 28 which rotates while revolving and the metal can 11 becomes the pattern transferred can 10 on which the micro protrusion and recess pattern 12 is formed.

Each time the micro protrusion and recess pattern 12 is transferred to the metal can 11 and thus the pattern transferred can 10 is produced, clogging and wear occur in the micro protrusion and recess parts 13 a of the stamper 35 and, when a certain number of the metal cans 11 have been processed, further transfer of the micro protrusions and recesses becomes impossible.

Therefore, while transfer processing of the metal can 11 is not performed, the stamper 35 formed with the micro protrusion and recess parts 13 a is wound on the take-up reel 37 to move the stamper 35 to the concave surface pressing mold 33 in a relative movement and thereby to add new micro protrusion and recess parts 13 a and dispose of an unusable portion of the stamper 35.

Since the unusable portion of the stamper 35 may be disposed of when transfer has become impossible, the amount of movement of the stamper 35 formed with the micro protrusion and recess parts 13 a may be adjusted in such a manner that the stamper 35 may be moved by only a little amount for each metal can 11 and, when the amount of movement has reached to a length corresponding to a predetermined number of metal can 11 at which transfer becomes impossible, the portion of the stamper 35 corresponding to the amount of movement may be disposed of or, alternatively, the stamper 35 may be moved every time transfer has been made to a predetermined number of metal cans 11 and, when the portion corresponding to the amount of movement has reached a predetermined number of metal cans at which transfer is no longer possible, this portion of the stamper 35 may be disposed of. It is also possible, when transfer has become impossible before the stamper 35 has been moved for a predetermined number of metal cans 11, to dispose of a portion of the stamper 35 corresponding to the entire transfer surface 14 b and renew this portion.

In this apparatus 20, the stamper 35 moves in a relative movement by winding it in the direction of transfer. Alternatively, the stamper 35 may be moved in vertical direction or may be moved in a relative movement by combining movement in vertical direction and movement in lateral direction.

The micro protrusion and recess patterns 12 formed on the pattern transferred can 10 by the relative movement of the stamper 35 have the quality of the patterns change gradually in the feeding direction of the metal can 11 (i.e., direction of transfer). More specifically, each time the patterns have been transferred to one can or plural cans, a portion of the patterns on the side of the portion of the stamper 35 which is to be disposed of becomes somewhat unclear and a portion of the patterns on the side of the stamper 35 which is to be supplied newly becomes clear. In case a portion of the stamper 35 corresponding to the entire transfer surface 14 b is disposed of and renewed, the quality of the entire micro protrusion and recess parts 12 is gradually deteriorated and the entire patterns become gradually unclear and this phenomenon is repeated.

Accordingly, by setting the amount of movement of the stamper 35 and the number of the metal cans on which transfer should be made in accordance with necessary quality as the micro protrusion and recess patterns 12 of the pattern transferred can 10, it is possible t manufacture the pattern transferred can 11 on which the micro protrusion and recess patterns 12 of a desired quality have been transferred.

Even in a case where the quality of the micro protrusion and recess patterns 1 changes in the direction of transfer of the metal can 11, it is possible to cause a predetermined pattern surface 14 a of the concave surface pressing mold 33 to be always positioned in front of new micro protrusion and recess parts 13 a whereby a predetermined pattern portion of the micro protrusion and recess patterns 12 can always be transferred clearly.

In this manner, the pattern transferred can 10 on which the micro protrusion and recess patterns 12 have been transferred is fed to the take-out position 39 by rotation of the disk 23 and is taken out from this position.

Thus, by forming the micro protrusion and recess parts 13 a on the stamper 35 and separately forming the pattern surfaces 14 a on the concave surface pressing mold 33, and transferring the micro protrusion and recess patterns 12 with the metal can 11 being held between the concave surface pressing mold 33 and the can holder 28, the micro-protrusion and recess parts in which clogging and wear have occurred can be disposed of and new micro protrusion and recess parts 13 can be supplemented whereby continuous transfer can be realized.

Since the stamper 35 on which the micro protrusion and recess parts 13 a are formed is thrown away, it is not necessary to rinse the micro protrusion and recess parts 13 a but it suffices to secure only a very short time period during which the stamper 35 is moved. Therefore, the pattern transferred can 10 formed with the micro protrusion and recess patterns 12 can be produced at a high speed.

Further, as compared with a conventional case where micro protrusion and recess parts are formed directly on pattern surfaces of a transfer mold and a surface treatment is applied for restraining wear, it is relatively easy to manufacture, by electroforming for example, only the band type transfer mold member 13 formed with the micro protrusion and recess parts 13 a. Therefore, the manufacturing cost of a transfer mold can be reduced and, in case the relief pattern needs to be changed, it can be changed easily by preparing only the concave surface pressing mold 33.

In this pattern transferred can 10, since the concave surface pressing mold 33 is formed separately from the stamper 35 formed with the micro protrusion and recess parts 13 a, individual protrusions and recesses of the micro protrusion and recess parts 13 a do not always meet with the pattern surfaces 14 a as viewed microscopically but more often do not meet with the pattern surfaces 14 a in normal transfer processing. Thus, transfer is made in a different manner from a case where micro protrusions and recesses are formed directly on the pattern surfaces.

In this apparatus 20 for manufacturing the pattern transferred can 10, since the micro protrusion and recess patterns 12 are transferred to the outer surface of the metal can 11 with the concave surface 14 b of the concave surface pressing mold 33 and the can holder 28, adhesion of the material of the metal can 11 to the stamper 35 can be restrained and, therefore, clogging is restrained and the life of the stamper 35 is increased and a large-scale production at a high speed can be realized.

Further, since the protrusions and recesses 14 c which are larger than the micro protrusions and recesses of the micro protrusion and recess parts 13 a are formed, by shot blasting for example, on the pattern surfaces 14 a of the concave surface pressing mold 33, the portion of the micro protrusion and recess parts 13 a corresponding to these protrusions and recesses 14 c only is transferred closely to the outer surface of the metal can 11 and, therefore, wear of the stamper 35 can be prevented as compared to a case where transfer is made with a flat surface and the life of the stamper 35 thereby can be increased for transfer.

In the apparatus 20 for manufacturing the pattern transferred can 10, pressing transfer can be made with lubricant provided between the stamper 35 and the metal can 11 and, by performing transfer in an atmosphere of lubricant such as lubricant added positively by providing a lubricant supply device or coolant put on an aluminum can during DI processing, adhesion of the material of the can is prevented and discharge of such material is facilitated whereby build-up due to clogging can be restrained and a large scale production at a high speed by continuous transfer can be realized.

As such lubricant, a lubricant added with oleic acid or lauric acid is preferable. Particularly, a lubricant added with oleic acid is effective for preventing build-up in an aluminum can. Oleic acid is often added to a coolant of a DI can and the same effect can be obtained in case transfer is made with a coolant adhered to the DI can.

As described above, according to the pattern transferred can and the method for manufacturing it of the invention, interference fringes (rainbow-colored hologram) can be observed on the trunk of a metal can which is smooth and has metal luster by transferring micro protrusions and recesses and, by combination with a pattern, picture and character, beautiful decoration which has not been found-before can be realized.

Then, another embodiment of an apparatus for manufacturing a pattern transferred can will be described with reference to FIG. 5 The same component parts as those described in the above described embodiment are shown by the same reference characters.

In this apparatus 40 for manufacturing a pattern transferred can, as different from the apparatus 20 already described, a pattern surface forming mold 14 provided opposite to a can holder 28 on which a metal can 11 is mounted has a convex surface.

In this apparatus 40, a disk 23 is fixed to a rotary shaft 22 extending through a frame 21 of the apparatus and the disk 23 is driven and rotated by a belt 27 which is provided between a pulley 25 of a motor 24 fixed to the frame 21 and a pulley 26 provided at the lower end portion of the rotary shaft 22.

A plurality (six in the illustrated example) of can holder 28 which constitute the press-supporting mold member 15 are provided at an equal interval in the circumferential direction and the metal cans 11 can be mounted on the can holders 28 by fitting each of the metal cans 11 on the can holder with the bottom of the metal can 11 up.

Each of the can holder 28 has a support shaft 29 projecting downwardly and the support shaft 29 is rotatably mounted on the disk 23 via a bearing 30 and a gear wheel 31 fixed to the support shaft 29 is in meshing engagement with a large gear 41 which is fixed to the frame 21.

By this arrangement, as the disk 23 is driven and rotated, each of the can holders 28 rotates on the support shaft 29 and revolves around the outer periphery of the disk 23 on the rotary shaft 22.

In the apparatus 40 for manufacturing the pattern transferred can, a convex surface pressing mold 42 which constitutes the pattern surface forming mold member 14 is fixed on the center side of the frame 21 in a position opposite to the entire length of the outer surface (i.e., the circumference) of the rotating can holder 28 which revolves around the outer periphery of the disk 23 or a part thereof in such a manner that the convex surface of the transfer surface 14 b is opposed to the can holder 28 on the inner peripheral side of the revolving orbit.

A stamper 35 in the form of a coil which constitutes the band type transfer mold member 13 passes along guide members 36 provided in the end portions of the stamper 35 and is disposed along the convex transfer surface 14 b. The stamper 35 in the form of a coil is wound on a rewind reel 36 and its forward end is fixed to a take-up reel 37. By an unillustrated take-up drive system, the stamper 35 is fed and wound on the take-up reel 37 so that a predetermined amount thereof is moved in a relative movement to the convex surface pressing mold 42.

In this case, since the stamper 35 in the form of a coil passes along the convex surface of the convex surface pressing mold 42, the stamper 35 can be caused to pass along the convex surface of the convex surface pressing member 42 in a simple way by applying tension to the stamper 35 whereby high speed feeding of the stamper 35 can be realized.

The convex surface pressing mold 42 is disposed in such a manner that the stamper 35 touches the outer surface of the metal can 11 mounted on the can holder 28 and pressing and transfer can be made between convex surfaces with the metal can 11 and the stamper 35 being held between the can holder 28 and the convex surface pressing mold 42.

In the disk 23 provided with six can holders 28 are provided a supply position 38 of the metal can 11 on the upstream side of the convex surface pressing mold 42 and a take-out position 39 of the metal can 11 on the downstream side of the convex surface pressing mold 42 and unillustrated automatic supply device and automatic take-out device are also provided.

The apparatus 40 for manufacturing the pattern transferred can, in some cases, is installed during the manufacturing process of the metal can and, in other cases, is installed while the metal can is not manufactured. In the former case, for example, the metal can 11 is supplied to the apparatus 40 for transfer processing in the state that lubricant is applied to the metal can 11.

Structure of other parts of the apparatus 40 is the same as the structure of the apparatus 20 which has been described above.

Operation of the apparatus 40 having the above described structure will now be described together with a method for manufacturing the pattern transferred can. Since the basic operation of the apparatus 40 is the same as that of the apparatus 20 using the concave surface pressing mold 33 already described, description will be made mainly on differences in using the convex type pressing mold 42.

First, the stamper 35 constituting the band type transfer mold member 13 formed with the micro protrusion and recess parts 13 a is positioned in front of the transfer mold 14 b by passing the the stamper 35 along the guide members 34 of the convex surface pressing mold 42.

Then, the motor 24 is driven to rotate the disk 23 and the metal can 11 is supplied to the supply position 38 and is mounted on the can holder 28 constituting the press-supporting mold member 15 which comes to the supply position 38 by fitting the metal can 11 on the can holder 28.

As the metal can 11 mounted on the can holder 28 arrives in front of the convex surface pressing mold 42, the metal can 11 is held and pressed between convex surfaces of the convex surface pressing mold 42 and the can holder 28 with the stamper 35 being in contact with the outer surface of the metal can 11 and transfer thereby is started. While the disk 23 is rotated before the outer periphery of the convex surface pressing mold 42, the pattern surface 14 a formed on the convex surface pressing mold 42 and the micro protrusion and recess parts 13 a of the stamper 35 are simultaneously transferred to the metal can 11 mounted on the can holder 28 which rotates while revolving and the metal can 11 becomes the pattern transferred can 10 on which the micro protrusion and recess pattern 12 is formed.

Each time the micro protrusion and recess pattern 12 is transferred to the metal can 11 and thus the pattern transferred can 10 is produced clogging and wear occur in the micro protrusion and recess parts 13 a of the stamper 35 and, when a certain number of the metal cans 11 have been processed, further transfer of the micro protrusions and recesses becomes impossible.

Therefore, while transfer processing of the metal can 11 is not performed before processing of a next metal can 11, the stamper 35 formed with the micro protrusion and recess parts 13 a is wound on the take-up reel 37 to move the stamper 35 to the convex surface pressing mold 42 in a relative movement and thereby to add new micro protrusion and recess parts 13 a and dispose of an unusable portion of the stamper 35.

Since the amount of movement and manner of movement of the stamper 35 formed with the micro protrusion and recess parts 13 a are the same as in the previously explained case where the concave surface pressing mold 33 is used, description thereof will be omitted.

In this apparatus 40 for manufacturing a pattern transferred can, the stamper 35 in the form of a coil which constitutes the band type transfer mold member 13 is wound along the convex surface of the convex surface pressing mold 42 and, therefore, in case an unusable portion is fed by relative movement of the stamper 35, passing of the stamper 35 along the convex surface can be made simply as compared with a case where the concave surface is used which requires a guide roller in the middle portion and a vacuum suction device. Passing of the stamper 35 can be made, for example, by applying tension to the stamper 35.

By this arrangement, although damage and build-up of the stamper 35 may increase to some extent as compared with a case where the concave surface is used, this does not become a serious problem because transfer of patterns is made while the stamper 35 itself is gradually disposed of. A high speed feeding of the stamper 35 can be realized by applying tension to the stamper 35 and the object of the invention, i.e., increasing speed of production and improving productivity thereby, can be achieved.

In this apparatus 40, the stamper 35 moves in a relative movement by winding it in the direction of transfer. Alternatively, the stamper 35 may be moved in vertical direction or may be moved in a relative movement by combining movement in vertical direction and movement in lateral direction.

The apparatus 40 for manufacturing a pattern transferred can performs, in addition to the above described operation and functional effects, the same operation and functional effects as those of the above described apparatus 20 for manufacturing a pattern transferred can.

As described above, according to the pattern transferred can and the method for manufacturing it of the invention, interference fringes (rainbow-colored hologram) can be observed on the trunk of a metal can which is smooth and has metal luster by transferring micro protrusions and recesses and, by combination with a pattern, picture and character, beautiful decoration which has not been found before can be realized.

In the above described embodiments, the pattern surface forming mold member is disposed on the outside of the can and the press-supporting mold member is disposed on the inside of the can. Alternatively, a press-supporting mold member having a concave or convex surface may be disposed on the outside of the can and a pattern surface forming mold member formed with a pattern surface may be disposed on the inside of the can and the can may be mounted on this pattern surface forming mold member for pressing and transfer.

The foregoing description has been made about an aluminum can and a steel can such as a tinplate can for drinks as an example. The cans are not limited to cans for drinks but the invention is applicable also to cans used for other purposes.

The metal can is not limited to a DI can which is formed by drawing but may be other metal cans such as an impact can which is formed by impact processing. The material of the metal can is not limited to steel such as tinplate and TFS or aluminum but may be other material so long as it is a metal material.

INDUSTRIAL APPLICABILITY

According to the present invention, interference fringes (hologram) and patterns including a picture and a photograph formed by micro protrusion and recesses can be transferred to a steel can such as a tinplate can or a TFS can or an aluminum can without being affected by clogging and a large scale production at a high speed can be realized. 

1. A pattern transferred can having micro protrusion and recess patterns transferred by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member.
 2. A pattern transferred can as defined in claim 1 wherein the micro protrusion and recess patterns are transferred to the can by moving the band type transfer mold member to the pattern surface forming mold member and the press-supporting mold member in a relative movement.
 3. A pattern transferred can as defined in claim 1 or 2 wherein micro protrusions and recesses of the micro protrusion and recess parts are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can.
 4. A method for manufacturing a pattern transferred can by touching a band type transfer mold member formed with micro protrusion and recess parts thereon on a can and holding and pressing the can and the band type transfer mold member with a pattern surface forming mold member and a press-supporting mold member thereby to transfer a pattern surface formed with micro protrusions and recesses to the can.
 5. A method for manufacturing a pattern transferred can as defined in claim 4 wherein the band type transfer mold member is moved in a relative movement to the pattern surface forming mold member and the press-supporting mold member thereby to renew the micro protrusion and recess parts of the band type transfer mold member and then the micro protrusion and recess patterns are transferred to the can.
 6. A method for manufacturing a pattern transferred can as defined in claim 5 wherein renewed micro protrusion and recess patterns are transferred to the can by renewing the micro protrusion and recess parts over a length which is equivalent to or shorter than the circumferential length of the can.
 7. A method for manufacturing a pattern transferred can as defined in any of claims 4-6 wherein protrusions and recesses which are larger than the micro protrusions and recesses of the band type transfer mold member are formed on the surface of either the pattern surface forming mold member or the press-supporting mold member.
 8. A method for manufacturing a pattern transferred can as defined in any of claims 4-7 wherein the micro protrusion and recess parts of the band type transfer mold member are formed in the shape of protrusions or ridges extending in parallel to the circumferential direction of the can.
 9. A method for manufacturing a pattern transferred can as defined in any of claims 4-8 wherein the micro protrusion and recess patterns are transferred to the can with lubricant provided between the band type transfer mold member and the can.
 10. A method for manufacturing a pattern transferred can as defined in any of claims 4-9 wherein the pattern surface forming mold member is disposed on the inside of the can and the band type transfer mold member and the press-supporting mold member are disposed on the outside of the can.
 11. A method for manufacturing a pattern transferred can as defined in any of claims 4-9 wherein the press-supporting mold member is disposed on the inside of the can and the band type transfer mold member and the pattern surface forming mold member are disposed on the outside of the can.
 12. A method for manufacturing a pattern transferred can as defined in any of claims 4-11 wherein the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a concave surface with a center of curvature thereof being located on the same side as the center of the can.
 13. A method for manufacturing a pattern transferred can as defined in any of claims 4-11 wherein the pattern surface forming mold member or the press-supporting mold member is formed as a mold member having a convex surface. 